A 3 ft (36 in) wide deck is likely too narrow to comfortably fit this toddler slide and still leave room to walk around it.
The assembled slide is approximately 61 in (155 cm) wide, so it would extend well beyond a 36-inch-wide deck.
For safe use, it's recommended to place the slide where there is additional clearance around it, especially at the sides and the end of the slide. If your deck is only 3 ft wide, it would not provide adequate walking space around the playset.
By vevor